Building 228WEST AREA ME62 – ELECTRICAL SUBSTATIONNew HVAC system

R. Bozzi / EN-CV

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Overview

• Reference documents:

• the engineering specification concerning the West Area substations upgrade (reference ELG-HVNET-EN-0142, rev. 1.0 dated 2015-03-04 – EDMS ref. 1304554 v.1)

• 228-R-001: battery room, users’ requirements

• temperature: 20÷25˚C (all year long)

• relative humidity: not controlled

• equipment heat load: null

• fresh air renewal: 180 m3/h

• emergency conditions 35˚C for 8 hours maximum

• no redundancy requested

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Overview

• 228-1-401: electrical room, users’ requirements

• temperature: 20÷30˚C (all year long)

• relative humidity: not controlled

• equipment heat load: 4644 W

• fresh air renewal: null

• emergency conditions 35˚C for 8 hours maximum

• no redundancy requested

• THE ABSENCE IN THE NEARBY OF CHILLED WATER AND THE DIFFICULTY TO PROVIDE HOT WATER RESULTED IN THE DECISION OF INSTALLING DIRECT EXPANSION SYSTEMS

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228-R-001

• Heating / cooling load calculation: MC4 software HvacCad 2009

• Cooling load calculation: ASHRAE Handbook 2001 - RTS Method

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228-R-001

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228-R-001

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228-R-001

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228-R-001

• A reversible split system will be provided (8,7 kWheat, 7,9 kWcool)

• Reference: Mitsubishi PCA-RP71KAQ (unité intérieur) et PUHZ-ZRP71VHA (unité extérieur) ou équivalent approuvé

• This system will:

• provide the cooling/heating during the whole year to maintain the temperature inside the room between 20°C and 25°C (the relative humidity is not controlled)

• provide 180 m3/h of treated fresh air

• The internal unit will be installed on the ceiling of the battery room. The external unit will be placed on the roof of the battery room 228-R-001 itself

• The system will be provided with its own regulation and control system.

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228-R-001

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228-R-001

• The extraction of the 180 m3/h air will be provided by an axial fan, wall mounted in the NW corner, in order to use the existing hole of the room where actually a very old, out of order, window split is installed. In case of interruption of the fresh air renewal a voltage-free contact will be made available inside the CV cubicle.

• A grille will be installed on the door for the following purposes:

• in case of fault of the wall mounted extraction fan the split system will however continue to supply outside treated air: the excess of air will escape through the grille (temperature is controlled, fresh air renewal is still ensured)

• in case of fault of the split system the extraction fan will continue to work: outside air (not treated) will enter in the room through the grille (temperature is not controlled, but fresh air renewal in ensured)

• An internal temperature transmitter will be installed for remote monitoring purposes

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228-1-401

• Heating / cooling load calculation: MC4 software HvacCad 2009

• Cooling load calculation: ASHRAE Handbook 2001 - RTS Method

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228-1-401

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228-1-401

• The very important gap between the winter heating needs and the summer cooling load could bring to select a strongly oversized system. Direct expansion systems have circa the same power in heating and cooling: in our case the leading factor is the heating need of 30 kW, which would mean to install a system with a cooling power of 28 kW circa, more than three times the effectively needed cooling load. The oversizing would result in the increase of the dimensions of the equipment (affecting the installation inside the room itself) and mainly in a more than doubled cost of installation.

• Then CV will provide only the cooling system, as already done in similar buildings (e.g. the BE91), where the heating was provided directly by EL.

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228-1-401

• A split system will be provided for cooling purposes only (11,9 kWcool)

• Refrence: Stulz MiniSpace EC Eco-Cool with Direct Free Cooling

• the temperature will be ensured only during the cooling period. This system will provide 3.600 m3/h of cooled air. The system could also operate in free-cooling in the following operating modes:

• free cooling (outside temperature between supply air set point and antifreeze temperature): outside air damper opens. Outside air flows through the filter directly into the unit, then into the room; compressor off. The return air and outside air dampers open if the outside temperature drops or thermal load is reduced. They mix return air with outside air and so maintain the supply air temperature; compressor off.

• extended free cooling (outside temperature above supply air set point): the cooling capacity is kept constant by increasing the air flow. Outside air damper open; compressor off.

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228-1-401

• mixed mode (outside temperature continuously increasing): if the fan reaches maximum speed and Extended Free Cooling is no longer sufficient, the compressor is switched on for support; outside air damper open; compressor runs in partial-load mode.

• cooling mode (outside temperature out of cooling and mixed mode range): the unit works in compressor mode; outside air damper closed.

• The internal unit will be placed near the entrance on the east side of the room, to be near to the roof of the building 228-R-001 where the external unit will be installed and to easily connect the outside air damper of the cooling system to the outside of the building. A ductwork will distribute the cooled air (the net height below the duct will 2,5 m circa). The return air is directly placed on the system itself, no ductwork is needed. The system will be provided with its own regulation and control system.

• One of the windows will be removed in order to install an overpressure damper for the free cooling operating mode.

• An outside temperature transmitter and an internal temperature transmitter will be installed for remote monitoring purposes.

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228-1-401

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228-1-401

• mixed mode (outside temperature continuously increasing): if the fan reaches maximum speed and Extended Free Cooling is no longer sufficient, the compressor is switched on for support; outside air damper open; compressor runs in partial-load mode.

• cooling mode (outside temperature out of cooling and mixed mode range): the unit works in compressor mode; outside air damper closed.

• The internal unit will be placed near the entrance on the east side of the room, to be near to the roof of the building 228-R-001 where the external unit will be installed and to easily connect the outside air damper of the cooling system to the outside of the building. A ductwork will distribute the cooled air (the net height below the duct will 2,5 m circa). The return air is directly placed on the system itself, no ductwork is needed. The system will be provided with its own regulation and control system.

• One of the windows will be removed in order to install an overpressure damper for the free cooling operating mode.

• An outside temperature transmitter and an internal temperature transmitter will be installed for remote monitoring purposes.

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ELECTRICITY

• La distribution électrique se fera depuis un coffret électrique principal qui sera neuf et à la charge du contractant. Le ou les départs vers les équipements à raccorder se feront depuis ce coffret principal.

• Le coffret comprendra les départs vers les équipements suivants:

• système de climatisation pour le local 228-1-401

• système de climatisation pour le local 228-R-001

• ventilateur axial d’extraction pour le local 228-R-001

• automate programmable du type WAGO

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BUDGET ESTIMATE

• 228-1-401: used as reference (DAI) - n. 5069272 - CLIMATISATION LOCAL bat. 959 – Date 24.09.2012 – TOTAL €39,950.00 

• Poste 1: Démontage des anciens equipements: unité existante, tourelle en toiture. 1,000 euro

• Poste 2: Fourniture, installation et mise en service de 2 Armoires de climatisation STULZ type MINISPACE EC TYPE : CCU 131A P=11,2 kW froid à condensation à air, avec soufflage en partie haute et reprise en façade . Fourniture et pose de réseaux de gaines Ø 250mm & Ø200mm équipés de 24 Grilles France AIR SFV21 525*75mm. 24,000 + 5,000 = 29,000 euro

• Poste 3: Fourniture, pose et mise en service d'un caisson d'extraction VIM référence KMDT05-IS 230 V avec filtre G4 Y compris réseau de gaines Ø160mm équipé de grilles d'aspiration. 4,000 euro

• Poste 4: Fourniture et pose d'un coffret electrique de commande et d'alimentation de l'ensemble des équipements. 5,000 euro

• Poste 5: Fourniture des dossiers techniques au format papier et electronique. 1,000 euro

• Country of origin: FR (40.0% ), DE (60.0% ),

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BUDGET ESTIMATE

THANKS